What event should I check for real-time call recording

Hello All,
I am running Asterisk 1.8.6 (FreePBX)
I configured both (incoming and outgoing) recording options to “Always”

using the Asterisk.NET Manager API that was in C# language,
how to get the file name of recorded file?
in what event should I check?

I tried to use MonitorStartevent and MonitorStopevent but it does not fired…

please help

thanks & regards